Processes for the simultaneous production of yeast and spirit



Patented Apr. 20,1954

PROCESSES FORTHE SIMULTANEOUS PRO- DUC'IION F YEAST AND SPIRIT Karl Schneider, Mannheim, Germany, assignor to Backhefe G. in. b. 11., Frankfurt am Main,.

Germany, a firm No Drawing. Application December 5, 1950, Serial No. 199,368

6 Claims. 1

According to. the prelent invention a process for. the-production together of yeast-.-and spirit lspro-vided, by whichthe purity ofthe spirit obtained and the quality and-quantity of the resultant yeastis improved.

In the known processes forthe. obtaining" together of yeast and spirit it is usual to attain some 20-50% of yeast and 23-12% of spirit in the spirits-yielding fermentation. The spirit concentration in the wort thus isv -25%. Thereafter a fermentation follows which takes place in the known way with or without the obtaining ofalcohol. In the former case the concentration of the alcohol in the wortattains an increase of about 0.2 to.(l.8% by volume.

According to the invention one: operates in such a way that one reaches conditions which hinder the growth of the yeast in the spirityielding fermentations therebyraising, considerably the alcohol concentration.. For this pur pose one may for example use in higher concentration substrates which are poor in or free from growth promoting and activating substances whichin fermentation .give rise toa. higher alcohol content. in thewort or alsobylimitingthe. oxygen supply by means. of a reduction in the quantity of air. The correspondingv higher al cohol concentration in the. wort can likewise. serve as a fermentation-hindering medium. Following removal of. the alcohol formed from the. yeast it is thenessential to increase the yeast witha fresh. introduction of fermentationhin dering so. that finally an. acceleration of the yeast growth is brought about by transferring to the usual fermentation conditions.

As the conditions hindering the growth of the yeast may be chosen singly or in combination the addition of diificultly fermentable substrates, a reduced quantity of substrate, theme of substrates, poor in or free from. growth promoting and activating substances, limitation of. the -nitrogen content, nitrogen removalor also'theem ploymentof an abnormally low temperature of about 12-22 C. in place of 26-3090.

Theusev accordin to the. invention of substrates poor in or free from growth promoting and activating substances in the spirit fermentation or minimal dosing of the oxygen introduction provesto be effective. Thealcohol concentration achieved in the spirit fermentation varies from about 4 to 9%. The conditions decreasing the growth of the yeast or of its ability to ferment or multiply can also happen at the beginning ofv the culture. The. h ndering effectswhich are active in; the spirit yielding fermentations have the result that the yeast hasto undergo a reduced hinderin treatment immediatelyaiter the removal of the alcohol. If first therefore a. slow breaking-up of the hindering takes place,.the yeast can:.be submitted to normal fermentation conditions; .by which it gives a yield higher than withztheiknown processes and has desirable improvements of quality, relative to durability; activity (ability of leavening) (oven activity). and, retention of ace tivity. The higher one chooses-'theconcentration of alcohol in the-wort and the-more effective the hindering of the'fermentation-of" the yeast in the second stage, themore theadvane tage of the process becomes optimal.

The process according to the: invention is especially suitable initheobtainingnf alcohol with a yield of about 5. to" 23% with a; simultaneous production of a desirable :quantity .of'yeast.

The alcohol obtained is substantially-- purer than. with the-knownprocesses whichare 03:1? ried out with simultaneous production of yeast and spirit. It can be: rectified withoutqany particular difficulty.

The economic value of theoperation according to the invention consists in that, with the same expenditure of energy: iour onfiye times the quantity of spirit can-be producedicompared with the known processes. Inthis wayby the use of finest distributed air considerablequan tities of waste steam and thus considerable quantities of energy are saved.

In order that theinvention-may' be well .understood the following examples are'given'only as illustrations:

Example I A strain of yeast of normal origin is introduced in a pure culture process:withoutfattening. The introduced yeast mixed with 5.90 kg: beet molasses. with the-additionoiiii kg; of d-i-ammonium phosphate at 26 (3.. and 31 111-1 01. 4.5-5: After A oi the: molasses *havebeen'lfermented; 3,500 kg..of molassesare so allowed'to' runinto the fermentation that the fermenting liquid turns between 7-8 Balli-ng and. the "'a;lcohol con tent or the ferment rises-44%. No nitrogen is added-and the quantityof phosphate added'is 15' kg. During the total time of the fermentation 50 cubic metres of air is introduced hourly into the fermentation mixture in the finestdistribu tion. After completion-0f thefermentation the ferment has an alcohol-content of 7.4%. The. yeast is separated from-the alcoholic wort by means of a pressure separator. The? yeast ob-= tained ififlowkg l isthe.pitching cr-rseeding yeast of. the. next fermentation stage which begins :at-

12 C. without a nitrogen-or phosphate-addition under weak aeration with 200 kg. molasses and is continued in the flowing process with hourly additions of 100-150 kg. molasses with a rising temperature up to 21 C. with hindering. 1000 kg. of molasses are used. For this one can use also wood sugar, sulphite lyes or cane-molasses. The hindering is stopped further by a stron running in of molasses, which amounts to 290300 kg. molasses hourly, by the addition of the corresponding quantities of nitrogen and phosphate and through strong aeration. In this phase the process uses 1590 kg. of molasses. The yeast obtained amounts to 3020 kg. the spirit obtained 1250 litres. The yields, calculated on 50% sugar are, yeast 44.7% and spirit 18.5%.

Example 2 Yeast is introduced into the pure culture process on corn wort or on molasses with the addition of malt germs. There'follows a spirit yielding fermentation on beet molasses which gives 200 kg. yeast. This fermentation serves as the start for a spirit fermentation with 5000 kg. of cane-molasses. The fermentations takes place as is described in Example 1. However only 5 to cubic metres of air are passed through hourly and 50 kg. of ammonium sulphate and 10 kg. diammonium phosphate are added to the fermentation material. After the end of the fermentation the wort has an alcohol content of 8.8%. In place of the cane molasses wood sugar molasses may be used in corresponding proportion. The yeast is separated in' a pressure separator and then follows a fermentation with hindrance as described in Example 1, with 1000 kg. beet molasses. The hindering lasts somewhat longer. Then follows the normal fermentation with 1500 kg. molasses. 3030 kg. yeast and 1700 litres of spirit are obtained. 8500 kg.'cf molasses were used with 48.5% sugar content, so that the yeast yield is 36.8% and the spirit yield is 20.6%. What I claim is: Q 1. A process of producing alcohol and yeast which comprises fermenting yeast in a medium of molasses under conditions-to produce an alcohol content of about 4-8.8% in the presence of air and without added nitrogen, separating said yeast from said alcohol, then fermenting said yeast in a medium of molasses at a temperature of about 12C. and gradually increasing said temperature to about 21 0., and thereafter fermenting said yeast in a favorable nutrient medium with added nitrogen, phosphate and strong aeration to promote the growth of yeast.

2. A process of producing alcohol and yeast which comprises fermenting yeast in a medium of molasses at about 26 C. and a pH of 4.5 to 5 ing into said yeast relatively small quantities of molasses at a time with weak aeration at a starting temperature of about 12 C. and gradually increasing said temperature to about 21 C. during the hindering fermentation, and thereafter adding relatively large quantities of molasses, nitrogen and phosphate together with strong aeration to promote a high yield of yeast.

4. A process for the production of alcohol and yeast which comprises introducing yeast into a solution of molasses in the absence of nitrogen and phosphates, fermenting the same in order to produce an alcoholcontaining wort of about 4% to about 9% alcohol by volume, separating said yeast from said'wort, then introducing into said I yeast relatively small quantities of molasses at a time with weak aeration at a starting temperature of about 12 C. and gradually increasing said temperature to about 21 C. during the hindering fermentation, 'and-ther'eafter adding relatively large quantities of molasses, nitrogen and phosphate together with strong aeration to promote a .high yield of yeast.

5. A process for the production of alcohol and yeast which comprises introducing yeast into a solution of molasses, maintaining a temperature of about 26 C. and adding suificient ammonium phosphate to provide a pH of 4.5 to 5.0, fermenting the same in order to produce an alcohol containing wort of about 4% to about 9% alcohol by volume, separating said yeast from said wort, then introducing into said yeast'relatively small quantities of molasses at a time with weak aeration at a starting temperature of about 12C. and gradually increasing said temperature to about 26 C. during the hindering fermentation, and thereafter addingrelatively large quantities of molasses, nitrogen and phosphate together with strong aeration to promote a high yield of yeast.

6. A process for the production of alcohol and yeast which comprises introducing yeast into a solution of molasses, fermenting the same in order to produce an alcohol containing wort in the presence of ammonium phosphate and under conditions to produce an alcohol content of about 48.8% in the presence of air and with: out added nitrogen, separating said yeast from said alcohol, then fermenting said yeast in a medium of molasses at atemperatureof about 12 C. and gradually increasing said temperature to about 21 C. and thereafter fermenting said yeast in a favorable nutrient medium with added nitrogen, phosphate and strong aeration to promote the growth of yeast.

3. A process for the production of alcohol and yeast which comprises introducing yeast into a solution of molasses, fermenting the same in order to produce an alcohol containing wort of about 4% to about 9% alcohol by volume, separating said yeast from said w'ort,-then introducof about 4% to about 9% alcohol by volume, separating said yeast from said wort, then introducing into said yeast a medium of sulphite lye with weak aeration at a starting temperature of about 12 C. and gradually increasing said temperature to about 21 C. during the hindering fermentation, and thereafter addingv relatively large quantities of molasses, nitrogen and phosphate together with strong aeration to promote a high yield of yeast.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,722,803 Klein July 30, 1929 1,767,646 Bratton June 24, 1930 1,774,546 Claassen Sept. 2, 1930 1,920,395 Jellinek Aug. 1, 1933 2,013,456 Braasch et al Sept. 3, 1935 2,059,980 Bennett Nov. 3, 1936 2,079,634 Schultz May 11, 1937 2,122,939 Hansen July 5, 1938 2,183,570 Irvin et al Dec. 19, 1939 2,304,471 Meyer et al Dec. 8, 1942 2,367,931 Delofi're Jan. 23, 1945 FOREIGN PATENTS Number Country Date Great Britain of 1932 

6. A PROCESS FOR THE PRODUCTION OF ALCOHOL AND YEAST WHICH COMPRISES INTRODUCING YEAST INTO A SOLUTION OF MOLASSES, FERMENTING THE SAME IN ORDER TO PRODUCE AN ALCOHOL CONTAINING WORT OF ABOUT 4% TO ABOUT 9% ALCOHOL BY VOLUME, SEPERATING SAID YEAST FROM SAID WORT, THEN INTRODUCING INTO SAID YEAST A MEDIUM OF SULPHITE LYEWITH WEAK AERATION AT A STARTING TEMPERATURE OF ABOUT 12* C. AND GRADUALLY INCREASING SAID TEMPERATURE TO ABOUT 21* C. DURING THE HINDERING FERMENTATION, AND THEREAFTER ADDING RELATIVELY LARGE QUANTITIES OF MOLASSES, NITROGEN AND PHOSPHATE TOGETHER WITH STRONG AERATION TO PROMOTE A HIGH YIELD OF YEAST. 